[OpenLayers-Users] Re: WMS over Google Maps when panning tiles not in synch

[Andreas Hocevar]

If you're using OpenLayers trunk from svn, you can use OpenLayers.Layer.GoogleNG instead of OpenLayers.Layer.Google. All tiles will then move in sync. See http://openlayers.org/dev/examples/google-ng.html for an example.

Andreas.

On Jul 24, 2011, at 22:02 , Alessandro Ferrucci wrote:

> I am trying to verify that I don't see this behavior with google maps
> v2.  I switched the google maps script to specify v=2 but I still get
> the delayed tile dragging.
> 
> On Sun, Jul 24, 2011 at 3:56 PM, Alessandro Ferrucci
> <alessandroferrucci at gmail.com> wrote:
>> I am experiencing the exact same of what this ticket says:
>> 
>> http://trac.osgeo.org/openlayers/ticket/2929
>> 
>> does this mean that currently it's an issue in google maps v3?
>> 
>> Thanks,
>> Alessandro Ferrucci
>> 
>> On Sun, Jul 24, 2011 at 3:50 PM, Alessandro Ferrucci
>> <alessandroferrucci at gmail.com> wrote:
>>> Hello,
>>> I have the following code
>>> 
>>>       var map;
>>>            var projectionWGS84 = new OpenLayers.Projection("EPSG:4326");
>>>            var projectionMercator = new OpenLayers.Projection("EPSG:900913");
>>>            // Avoid pink error tiles
>>>            OpenLayers.IMAGE_RELOAD_ATTEMPTS = 3;
>>>            OpenLayers.Util.onImageLoadErrorColor = "transparent";
>>> 
>>>            function init(){
>>>                var options = {
>>>                    projection: new OpenLayers.Projection("EPSG:900913"),
>>>                    displayProjection: new OpenLayers.Projection("EPSG:4326"),
>>>                    units: "m",
>>>                    maxResolution: 156543.0339,
>>>                    maxExtent: new OpenLayers.Bounds(-20037508,
>>> -20037508,20037508, 20037508),
>>>                    restrictedExtent: new
>>> OpenLayers.Bounds(-164.88281,5.09094,-41.39648,52.69636).transform(projectionWGS84,projectionMercator),
>>>                    controls:[
>>>                        new OpenLayers.Control.Navigation(),
>>>                        new OpenLayers.Control.ArgParser(),
>>>                        new OpenLayers.Control.Attribution(),
>>>                        new OpenLayers.Control.PanZoomBar({ position:
>>> new OpenLayers.Pixel(2, 15) }),
>>>                        new OpenLayers.Control.Scale($('scale')),
>>>                        new OpenLayers.Control.LayerSwitcher(),
>>>                        new OpenLayers.Control.MousePosition(),
>>>                        new OpenLayers.Control.Permalink()
>>>                    ]
>>>                };
>>>                map = new OpenLayers.Map('map',options);
>>>                var googleHibridLayer = new OpenLayers.Layer.Google(
>>> "Google Hibrid", {type: google.maps.MapTypeId.HYBRID,
>>> 'sphericalMercator': true,isBaseLayer: true } );
>>>                var googleStreetLayer = new OpenLayers.Layer.Google(
>>> "Google Street", {'sphericalMercator':true} );
>>>                var addressLayer = new OpenLayers.Layer.WMS(
>>>                "Addresses", "<WMS SERVER HOSTNAME>",
>>>                {
>>>                    LAYERS: 'cira:address',
>>>                    STYLES: '',
>>>                    format: 'image/png',
>>>                    tiled: true,
>>>                    transparent:true,
>>>                    tilesOrigin : map.maxExtent.left + ',' +
>>> map.maxExtent.bottom
>>>                },
>>>                {
>>>                    buffer: 10,
>>>                    displayOutsideMaxExtent: true,
>>>                    isBaseLayer: false
>>>                }
>>>            );
>>> 
>>> map.addLayers([googleStreetLayer,googleHibridLayer,addressLayer]);
>>>                var USABounds=new
>>> OpenLayers.Bounds(-124.731,24.956,-66.97,49.372);
>>>                USABounds.transform(projectionWGS84,map.getProjectionObject());
>>>                map.zoomToExtent(USABounds);
>>>            }
>>> 
>>> The WMS looks to be overlaying fine, but when I pan the map the tiles
>>> look like they are "shifting plates" meaning they look like they are
>>> moving independently and it looks quite ugly.
>>> 
>>> I have tried adding "projection: new
>>> OpenLayers.Projection("EPSG:900913")," as an option to the WMS layer
>>> itself thinking maybe that would fix it but it did not.
>>> 
>>> I'm using stable Openlayers 2.10
>>> Any ideas?
>>> 
>>> Thank you,
>>> --
>>> Signed,
>>> Alessandro Ferrucci
>>> 
>> 
>> 
>> 
>> --
>> Signed,
>> Alessandro Ferrucci
>> 
> 
> 
> 
> -- 
> Signed,
> Alessandro Ferrucci
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-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.